This experimental study will test the effectiveness of a school based health education curriculum and health care referral system in increasing the knowledge of 12-15 year old adolescents concerning AIDS and sexuality and in decreasing those behaviors putting them at greater risk for acquiring HIV, This large scale interventional study (N= 3500 students) is based on 4 years of similar research by the principal investigation in 2 different school districts. A pre-test post-test design with repeated measures will be used to test the effect of professional or peer taught information with health referral, or control conditions. Existing health education classes (N = 150) will be randomly assigned to treatment conditions. Data will assess knowledge and self reports of behavior as well as health care system use and type of medical services provided. Further, a subset of the sample (N = 300) will participate in extensive interviews to test models examining the effect of intervention in relation to individual interpersonal and life background characteristics. Data analyses will include correlated T-tests, analysis of variance and covariance, and casual modeling. This study addresses the urgent need for effective interventions concerning AIDS and sexuality among adolescents, considers for whom particular interventions are most effective and includes feasibility issues of placing the study in the existing context of the school system.